Basic properties of refractory material for steel making

As we all know that refractory material is of various kinds and is widely used and also of great importance in steel industry. The following are some refractories commonly used in steel industry summarized by Changxing Refractory engineers.

(1) Refractories for converter

Magnesia carbon brick is used for furnace cap, tapping converter mouth, before and after the surface, weld pool and bottom; high strength magnesia carbon brick is used for trunnion and slag line. Usually the MgO content in magnesia carbon brick is 70 ~ 75%, graphite is 16 ~ 20%, bulk density is 2.8 ~ 2.9 g/cm3, compressive strength is 25 ~ 30 MPa. The elements of high strength magnesia carbon brick are the same elements as magnesia carbon brick, but its compressive strength should be 30 ~ 42 MPa.

(2) Refractories for electric furnace

Furnace hearth, furnace slope and molten pool are overall rammed with magnesia clinker, or constructed with magnesia brick which is made of magnesia carbon brick and tar asphalt; high-quality magnesia carbon brick is used for hot and slag line area; magnesia brick and magnetite chrome brick are used for tapping hole and the two sides of furnace door; high alumina bricks or high alumina uncalcined brick are used for furnace cover.

(3) Refractories for UHP EAF

For permanent lining of ultra high power EAF, using magnesium stone; for furnace doorjamb, using magnesia chrome brick; for slag line, eccentric bottom and molten pool, using magnesia brick; for hot spots, furnace wall and tapping hole, using magnesia carbon brick; for furnace cover, using high alumina brick; for tapping hole filler, using high ankerite filling material.
According to the working conditions of various steel furnaces, it can be proved that the refractory material working circumstance is very bad. Therefore, whatever refractories are used, it must possess the following properties.

  • High temperature resistant and high refractoriness.
  • Erosion and erosion resistance to high temperature molten steel and slag.
  • The steelmaking furnace works discontinuously, thus requires refractory material with good thermal shock resistance and spalling resistance.
  • High mechanical strength, can withstand impact of furnace tilting and furnace charge loading with no damage.


steel making furnace

The refractory materials should be able to withstand

  • High temperature
  • Sudden changes in temperature
  • Load at service conditions
  • Chemical and abrasive action of phases

The refractory material should not contaminate the material with which it is in contact.

Some of the most common examples of refractory materials include the following:

Fireclay refractories
High alumina refractories
Silica brick
Magnesite refractories
Chromite refractories
Zirconia refractories
Insulating materials, and
Monolithic refractories.

Based on the service conditions and temperature ranges, a large number of refractory materials are used in applications that include ovens, boilers, kilns, and conventional industrial furnaces.

steel factory steel making

FAQ:

What is refractory material?

In materials science, a refractory (or refractory material) is a material that is resistant to decomposition by heat, pressure, or chemical attack, and retains strength and form at high temperatures. Refractories are polycrystalline, polyphase, inorganic, non-metallic, porous, and heterogeneous.

How do you select refractory materials?

Refractories should have good thermal shock resistance. Refractories should have stable volume at high temperature and the residual expansion and contraction should be small. Heat capacity, thermal expansion coefficient, thermal conductivity and other thermal properties should meet the requirements.

Which of the following is an example of a refractory material?

The basic refractory materials include alumina, silica, magnesia and lime.

What is the best refractory material?

Hafnium carbide is the most refractory binary compound known, with a melting point of 3890 °C. The ternary compound tantalum hafnium carbide has one of the highest melting points of all known compounds (4215 °C).

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